Instability of the cavitating flow in a venturi reactor
Instability of the cavitating flow in a venturi reactor
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DOI：
10.1088/0169-5983/42/5/055503
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发表时间：
2010-07
影响因子：
1.5
通讯作者：
Hoseyn Sayyaadi
中科院分区：
文献类型：
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作者：
Hoseyn Sayyaadi
在文丘里管中对空化流动的不稳定性进行了实验研究。利用高速摄影技术观察了文丘里腔内空化流动的波动过程。采用光强对比技术对序列图像进行分析，并对每张图像的空化长度进行评价。确定了在指定工况（空化数和操作压力）下的时间空化长度波动矢量。利用快速傅里叶变换（FFT）方法获得了振动的频率分量。得到了空化数和操作压力对斯特罗哈尔数和波动幅度的影响。与操作压力的影响相比，空化数对空化流波动特性的影响较大。在较低空化数下，观察到云状空腔的周期性分离、脱落和坍缩，并伴有再入射流运动。在较高的空化数下，观察到具有正弦模式的简单波动模式。
The instability characteristics of cavitating flow were experimentally investigated in a venturi tube in a recirculating flow loop. The fluctuation process of cavitation flow in the venturi was observed using high-speed photography. The sequential images were analyzed using the light intensity comparison technique and the cavitation length for each image was evaluated. The temporal cavitation length fluctuation vectors were determined at the specified operating condition (the cavitation number and operating pressure). The frequency components of oscillation were obtained using the fast Fourier transform (FFT) method. The effects of cavitation number and operating pressure on the Strouhal numbers and amplitudes of fluctuations were obtained. It was found that cavitation number has a major effect on the fluctuation characteristics of the cavitating flow in comparison with the effect of operating pressure. It was observed that at lower cavitation numbers, periodic separation, shedding and collapsing of the cloud-like cavities are observed together with the re-entrant jet motion. At higher cavitation numbers, the simple fluctuation mode with a sinusoidal pattern is observed.